Conching devices may be designed as dry conching devices or as liquid conching devices. It is preferred to use conching devices that can be operated both as dry conching devices and liquid conching devices. With such a conching device as it has become known from DE-A 36 26 732, refining tools with refining blades extending diagonally to the trough wall are provided, which refining tools serve as scrapers or wipers for the dry treatment when the direction of rotation is reversed. The conching devices can have only one rotor in a trough compartment assigned to it, or else a plurality of rotors in trough compartments respectively assigned to them. When a conching device is employed which, by changing the direction of rotation of the rotors, can be operated both as a dry conching device and as a liquid conching device, the chocolate mass will first assume a dry-pasty condition, whereupon it will turn into a viscous-plastic condition to finally change into a liquid condition. With such a conching of the chocolate mass by means of the mechanical action of the rotors, a heating and aeration will be accomplished. When using this arrangement, for example a volatilization of organic acids, such as acetic acid, and also a desired oxidation of flavorings will result. Moreover, a mixing effect and a rounding off of the particles will be achieved. However, such a conching process is extremely time-consuming. Thus, fine chocolate masses will have to be conched up to 48 hours. This is aggravated by the fact that chocolate masses of identical recipe, of the same comminution rate, and of the same temperature will often have completely different viscosities, which has a considerable influence upon the conching process.
For a shortening of the conching process, it has already been suggested, according to DE-A 39 34 047, to adjust the speed of the driving motor in dependency upon a preselectable motor current, so that the energy consumed during a conching process may be adjusted to the different states of aggregation of the chocolate mass.
It is an object of the present invention to provide a method for operating a conching device in which the period of time of a conching process is exactly adapted to the chocolate mass contained within the trough, as well as to provide an arrangement for carrying out the method.